Running your own business usually()working long hours.
A. includes
B. involves
C. contains
D. comprises
反应器床层温升过大,有可能引起催化剂床层“飞温”,引发事故。()
Houston experienced a()growth after the war.
A. broad
B. mechanical
C. wide
D. spectacular
一般来说,GPS接收机硬件的组成部分有主机、天线和()
A. 网络
B. 软件
C. 电源
D. 系统